Genetic diversity

• What is genetic diversity?

  Number of different alleles in a population
• Describe the process of natural selection:

  • a random mutation results in a new allele of a gene
  • This leads to increased reproductive success
  • This means that over many generations the frequency of the allele increases
• What is a mutation?

  Any changes in a DNA base sequence
• What are the two types of mutations?

  • substitution
  • Deletion
• what is substitution mutation?


  where one nucleotides in the DNA sequence is replaced by another one. The substituted nucleotide may code for the same amino acid
• what is deletion mutation?

  When a nucleotide in the DNA sequence is lost. Different amino acids coded for.
• what are the two types of chromosomal mutations?

  • polyploidy
  • Non- disjunction
• what is polyploidy mutation?

  a mutation where an organism has more than two sets of chromosomes
• what is non-disjunction mutation?

  occurs when chromosomes fail to separate correctly during meiosis
• what does it mean if something is homologous?

  Similar in structure, position, or function due to shared ancestry.
• What is adaptation?

  Features or characteristics which provide and advantage to an organism in its habitat
• What is a phenotype?

  The physical characteristic of an organism
• What is a genotype

  The combination of alleles an organism has
• What is a gene?

  A section of DNA that codes for a polypeptide
• what is an allele?

  different versions of the same gene
• what is a population?

  A group of individuals of the same species that live together and are able to breed with one another
• what is natural selection?

  the process where the fittest species in their environment are able to pass down their genes for future generations
• what is the process of evolution via natural selection?

  • there‘s a variety of different phenotypes within a population
  • An environmental change occurs and as a result selection pressure changes
  • Some individuals possess advantageous alleles which give them a selective advantage and allow them to survive and reproduce
  • The advantageous alleles are passed on to their offspring
  • Over time, the frequency of alleles in a population changes and this leads to evolution
• What are the types of selection?

  • directional
  • Stabilising
• What are the types of adaptation?

  Anatomical: features of organisms we can see

  Behavioural: behaviours of organisms

  Physiological: features involving internal structures e.g. Metabolism
• what is intraspecific variation?

  variation within a species
• what is interspecific variation?

  variation between different species
• what is stabilising selection?

  when selection favoured average individuals. this preserves the characteristics of the population
• what is directional selection?

  when selection favoured individuals that vary from the mean. this changes the characteristics of he population
• what is adaptation?

  features or characteristics which provide an advantage to an organism in its habitat